When thinking about engines in general, air filters are a common consideration. That means that outboard users sometimes ask whether outboard motors have air filters. The answer to this question is below:
Outboard motors do not come with air filters but some people add them to prevent debris like bugs getting into the engine. Outboard manufacturers don’t include air filters since outboards are used on water where there is almost no dust so there is no real need to filter the air.
In this sense, not having an air filter on an outboard engine means a cost saving for the manufacturer, keeping the cost down for the customer, too, and also then having one less item to check and monitor for problems.
That said, you can buy an air filter for your outboard, but only for specific reasons, as we’ll look at below.
What is an air filter on a motor for?
An air filter stops elements like dust and grit from getting into an engine, which is particularly a problem for cars and other automobiles given that they are running on roads where dust and particles fly up all the time.
As you can imagine, doing the same on an outboard motor is not needed since the marine environment does not have the same issues with dust or other particles being churned up as it is running.
Even though you may store your outboard in a dusty environment, since the engine will not be run much in a dry, dusty environment, it then does not need the benefit of an air filter.
When You Need an Air Filter for Outboard
You can also use the gauze-type outboard air filter for preventing bugs and other insects getting into the motor, as they are the main problem outboard users have.
This Mercury outboard motor air filter gauze on Amazon is an original engine manufacturer part and does the trick for those outboards.
You might also want a type of air filter for your outboard to prevent foam getting into the engine from the ORM as the foam breaks down over time.
This would stop debris getting in and gradually blocking it up.
Outboard Operating Environment & Why Air Filters Are Not Usually Needed
Outboard motors are only really used on water, other than for testing or maintenance, so it makes sense that outboards do not have air filters with this in mind.
Yes, there will be some dust in the garage or on dry land where you might need to test or fix your outboard, but this will be minimal.
Furthermore, cars churn up dust on roads and actively play a part in pushing it into the engine compartments every time they are driven, which makes the dust get into various parts of the system.
Outboards do not do this, meaning that their engines do not need to filter the air coming into them since there is almost no dust to catch or worry about.
On the other hand, outboards have to deal with the problem of both corrosion from salt water that gets into the system as well as moisture from all types of water. This can lead to rust and is therefore one of the main points of concern for an outboard owner regarding maintenance and keeping a good engine that last a long time.
For more on cleaning your outboard motor, be sure to check out my breakdown on flushing your outboard motor with vinegar – it’s a cheap, household product but is it safe for your outboard? Find out now!